Air-brake system



2 Sheets-Sheet 2.

H. E. HUNT. AIR BRAKE SYSTEM (No Model.)

No. 545,295. Patented Aug. 27,1895.

UNITED STATES PATENT. OFFICE.

HERBERT E. HUNT, OF PITTSBURG, PENNSYLVANIA.

AIR-BRAKE SYSTEM.

SPECIFICATION forming part of Letters Patent No. 545,295, dated August27, 1895.

Application filed December 24, 1894. Serial No. 532,759- (No model?cross-section on the line III III of Fig. 1.

Fig. 4 is a plan view of the valve-disk, and Fig. 5 is a diagrammaticview of my preferred system.

My invention relates to the air-brake systems for use upon electric,cable, and other street-cars, wherein straight air is used, and isdesigned to provide a valve which may be operated by the conductor fromany part of the car, and which shall bring the car to a stop as quicklyas possible.

In the drawings, 2 represents the valve-casing having an inner flat seatagainst which is pressed the upper face of the disk-valve 3. In thiscasing are several openings, of which 4 is the supply-port leading airfrom the reservoir into the lower end of the casin g, and 5 is the portleading to the cylinder which operates the sand-snpply to the wheels ofthe car, while port 6 leads to a whistle and port 7 to thebraking-cylinder. The disk 3 is provided with holes or through-ports 8,9, and 10 and with a grooved port 11. The valve-seat is provided with aport 13 leading to the whistle-pipe, ports 14. and 14 leading to thesand-supply cylinder, a port 15 leading to the brake-pipe, and anexhaust-port 16 leading into a recess having an opening 17 leading tothe atmosphere. Bridges 17' are provided, as shown, between the ports13, 14, 15, and 16 to cut off inter-communication between these ports.The disk-valve is rotated by a lever 18, applied to a rotary stem 19,which extends through the valve-casing, and to hold the valve in placewhen there is no pressure in the chamber I provide the light spiralspring 20, pressing against the under face of the disk. There arepreferably provided two stopshoulders 21 and 22 on the valve-casing,adapted to engage a lug 23 upon the operating-la ver at the oppositelimits of motion of the valve. The ports in the valve-seat are sorelated in position to each other that when the valve is at oneextremity of its motion and in its normal position none of the ports inthe valve register with those in the seat except the grooved port 11,which connects the ports 14 and 16. When the valve-lever is moved fromthis position, the port 8 registers with the port 13, thus sounding thewhistle, and at the same time the port 9 registers with the port 14,thus operating the sand-releasing cylinder and supplying sand to thewheels. As the lever passes on, these ports are cutoff and the port 10comes into register with the port 15, thus connecting the air-reservoirwith the brake-cylinder and setting the brake. A spring is preferablyconnected with the actuating-lever 18 to force it back to its originalposition as soon as released, upon which the ports are all thrown out ofregister, except that the port 11 connects ports 14 and 16, thusexhausting the air from the sand'supply cylinder. The air in thebrake-cylinder is exhausted by the motorman by means of the ordinarythree-way valve in the cab. The lever 18 is operated by a cord, whichpreferably extends the entire length of the car, so that the valve maybe operated from any point in the car, the valve itself being locatedbeneath the seat or in any other convenient locality. I preferablyemploy for this emer gency-valve the auxiliary reservoir 2% of Fig. 5,in which figure 25 is the main reservoir, and 26 are check-valves in thesupply-pipe to each.

27 is the supply-pipe leading to the reservoir, and 28 the pipe leadingfrom the main reservoir to the motormans valve.

By this system the emergency-valve is entirely independent of the usualbraking system, and the auxiliary reservoir can never be exhaustedexcept by the emergency-valve itself, and hence is always ready forsuchemergency.

The advantages of my valve and system will be apparent to those skilledin the art, since, in the event of the necessity of a quick stop, theconductor may throw on this valve from any part of the car, and the airis applied immediately, the wheels being sanded to give them a betterhold while the brakes are applied.

Many changes may be made in the form, construction, and arrangement ofthe parts of my device by the skilled mechanic Without departing fromthe invention, since lVhat I claim is- 1. In an air-brake system, thecombination with a whistle, a braking cylinder and a sanding cylinder,of a valve having an inlet from the air reservoir, and ports leading to'each of said cylinders and Whistle; substantially as described.

2. In an air-brake system, the combination with a braking cylinder and asanding cylinder, of a valve having an inlet from the air reservoir,ports leading to each of said cylinders, and an exhaust port for thesanding cylinder; substantially as described.

3. In an air-brake system, a main reservoir, and an auxiliary reservoir,having a connection thcrebetween provided with a checkvalve arranged toprevent back flow from the auxiliary reservoir, a supply pipe leadinginto said connection, a pipe leading from the main reservoir to a valvecontrolling the brakecylinder and a pipe leading from the auxiliaryreservoir to an emergency valve controlling the brake-cylinder;substantially as described.

4. In an air-brake system, the combination with a braking cylinder and asanding cylinder, of an emergency valve arranged to first admit air tothe sanding cylinder and there after to the brake-cylinder, said valvehaving a port arranged to exhaust the sanding cylinder after the air iscut off from the brakingcylinder; substantially as described.

5. In an air-brake system, the combination with a whistle, a sandingcylinder and a braking cylinder, of a valve arranged to admitair firstto the Whistle and sanding cylinder and thereafter to the brakingcylinder; substantially as described.

In testimony whereof I have hereunto set my hand.

HERBERT E. HUNT. Witnesses:

H. M. CoRWIN, W. B. CoRWIN.

